<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>自定义函数与调用</title>
</head>
<body>
    <script>
        function getSum(n,m){
            var sum = 0;
            for(var i =n; i<= m;i++){
                sum += i;
            }
            console.log( n +' - '+ m +' 之间的数相加为:'+sum);
        } 
        getSum(5,10);
        getSum(100,1000);
    </script>
</body>
</html>